when we try to understand why someone joins an Islamist party, we tend to think of it as, "Is this person interested in power or community or belonging?" But sometimes it's even simpler than that. It [can be] about a desire for eternal salvation.

Again, something major is missing here. Between "power or community or belonging" and "eternal salvation", there is also a desire for a non-corrupt, just, pro-welfare government. Of course, a self-described liberal member of the Brookings Institution will be unwilling to see any system Western resp. pro-Western described as "technocratic, liberal democracy" as a corrupt, unfair, poverty-perpetrating abomination.